In the experiments of live canine subjects, the punctures were successful in 2 attempts in 7 beagle dogs and in 1 attempt in the remaining 2 dogs. https://www.selleckchem.com/products/urmc-099.html The puncture time of needle from hepatic vein to portal vein was 5-10 s in the phantom experiments and 10-30 s in the canine experiments.
The feasibility of AR-based navigation facilitating accurate and successful portal vein access in preclinical models of TIPS was validated.
The feasibility of AR-based navigation facilitating accurate and successful portal vein access in preclinical models of TIPS was validated.To quantitatively analyze the impact of intrahepatic venovenous shunt (IHVS) on hepatic venous pressure gradient (HVPG) measurement.
From 2015 to 2019, 222 HVPG measurements performed during transjugular intrahepatic portosystemic shunt creation were eligible for this study. Digital subtraction angiography (DSA) software color-coded each pixel of a two-dimensional DSA series by time-intensity curve to classify IHVS. Different degrees of IHVS were found in 36.5% of patients (81/222). Mild IHVS was found in 10.8% of patients (24/222), moderate IHVS was found in 10.8% of patients (24/222), and severe IVHS was found in 14.9% of patients (33/222).
Mean wedged hepatic vein pressure (WHVP) and HVPG were significantly lower in patients with IHVS compared with patients without IHVS (WHVP 17.78 mm Hg ± 7.00 vs 24.89 mm Hg ± 8.69, P= .001; HVPG 11.93 mm Hg ± 5.76 vs 18.6 mm Hg ± 6.85, P &lt; .001). Mild IHVS had little effect on WHVP and HVPG. Mean WHVP and HVPG were 11 mm Hg lower in patients with moderate IHVS (WHVP 20.38 mm Hg ± 8.38 vs 31.5 mm Hg ± 9.39, P= .026; HVPG 13.88 mm Hg ± 6.33 vs 25.00 mm Hg ± 9.81, P &lt; .001) and 15 mm Hg lower in patients with severe IHVS (WHVP 13.45 mm Hg ± 5.28 vs 28.64 mm Hg ± 6.38, P= .017; HVPG 8.27 mm Hg ± 3.85 vs 23.45 mm Hg ± 6.95, P &lt; .001) than mean portal vein pressure and portal vein gradient.
For patients with moderate or severe IHVS, HVPG might greatly underestimate the actual value of portal vein pressure, and the portal vein should be catheterized to measure portal pressure.
For patients with moderate or severe IHVS, HVPG might greatly underestimate the actual value of portal vein pressure, and the portal vein should be catheterized to measure portal pressure.In this paper the biomechanical response of a novel dental preparation technique, referred to as the Anatomic-Functional-Geometry treatment (AFG), is investigated through a 3D nonlinear finite-element modelling approach. A comparative investigation against a standard technique employed in dental clinical practice is carried out, by simulating typical experimental mechanical tests and physiological functional conditions. Failure mechanisms of treated tooth models are investigated through a progressive damage formulation implemented via a displacement-driven incremental approach. Computational results clearly show that AFG-treated teeth, as a consequence of a more conservative morphological preparation of the tooth, are characterized by more effective crown-dentin loading transfer mechanisms, higher fracture strength levels and more homogeneous stress patterns than the standard-treated ones, thereby opening towards widespread clinical application.The fields of Minimally Invasive Surgery (MIS) and Natural Orifices Transluminal Endoscopic Surgery (NOTES) strive to reduce the level of invasiveness by entering the body through smaller incisions and natural orifices. Hyper-redundant snake-like instruments can help in this pursuit of reducing invasiveness. Such instruments can pass along multi-curved pathways through the body without any support or guidance from its anatomical environment. In this way, the width of the surgical pathway and thus the invasiveness of the procedure can be reduced significantly. This is referred to as Follow-the-Leader (FTL) motion. Generally, surgical instruments intended for FTL-motion are robotic systems that require medical grade actuators, sensors, and controllers, driving up costs and increasing their footprint in the operation room. Our goal was to discard the need for these elements and develop a non-robotic instrument capable of FTL-motion along pre-determined paths. A proof of concept prototype called MemoFlex II was developed, consisting of a cable-driven hyper-redundant shaft that is controlled via four physical tracks. The MemoFlex II was able to perform 3D FTL-motion along pre-determined paths. Among other things, this study reports on a Ø8 mm shaft containing seven segments and 14 degrees of freedom (DOFs) following several multi-curved paths with an average maximal footprint between 11.0 and 17.1 mm.Sigmoid sinus diverticulum (SSD) is a common pathophysiology of pulsatile tinnitus (PT) and mainly treated by SSD reconstruction surgery. The degree of reconstruction is an important indicator of SSD reconstruction surgery, but its impact on the effect of SSD reconstruction is unclear. This study aimed to clarify the effect of the degree of SSD reconstruction on diverticulum reconstruction surgical treatment. One patient-specific case (control subject) was reconstructed based on the computed tomography angiography (CTA) images of patients with PT. The SSD reconstruction degree was used as a new index in this study. And the case of 30% (case 1), 60% (case 2), and 100% (case 3) of the diverticulum reconstruction degree of control subject were constructed. Transient-state computational fluid dynamics was performed. Wall pressure distribution, wall average pressure (Pavg) of SSD, flow pattern (velocity streamlines and velocity vector), wall shear stress (WSS) and averaged WSS (WSSavg) were calculated and used in change in the diverticulum is small, and the PT may have remained. SSD may be caused by high-speed blood flow.Mechanical properties and microstructural modifications of vessel tissues are strongly linked, as established in the state of the art of cardiovascular diseases. Techniques to obtain both mechanical and structural information are reported, but the possibility to obtain real-time microstructural and macrostructural data correlated is still lacking. An experimental approach to characterize the aortic tissue is presented. A setup integrating biaxial traction and Small Angle Light Scattering (SALS) analysis is described. The system was adopted to test ex-vivo aorta specimens from healthy and aneusymatic (aTAA) cases. A significant variation of the fiber dispersion with respect to the unloaded state was encountered during the material traction. The corresponding microstructural and mechanical data were successfully used to fit a given anisotropic constitutive model, with satisfactory R2 values (0.97±0.11 and 0.96±0.17, for aTAA and healthy population, respectively) and fiber dispersion parameters variations between the aTAA and healthy populations (0.